Aaron Blake at the Washington Post helpfully points out that the Republicans gave up on their government shutdowns in 1995 and 2013 when their poll numbers with the American people crumbled. In both of those precedents, the numbers looked about how they look now, with an overwhelming and disproportionate number of respondents blaming the GOP for the shuttered government and disapproving of their goals. One important thing is different this time, however. This time, the president is a Republican and it’s not the congressional Republicans who are the driving force behind the shutdown. Senate and House Republicans can’t just open the government solely based on their assessment of the politics. Instead, they have to contend with Donald Trump. They could override his veto, but that’s a different kind of hurdle.

Until today, Trump’s approval numbers had been declining slowly but still holding at around 40 percent. A handful of recent surveys had him falling into the thirties, but they looked like outliers. But now the new AP/NORC survey has him at 34 percent and he’s fallen below the 40 percent threshold in the FiveThirtyEight aggregate of polls. Even Rasmussen and Hill-HarrisX have Trump at his lowest mark despite being consistent outliers in his favor.

Blake made the polling comparison to previous shutdowns to make the point that the GOP seems to have reached a point of public opprobrium that was sufficient to break their will in the past. It’s a bit like predicting the point at which water will boil, except that we’re now at a different altitude.

However you look at it, things are getting hot. There are some vulnerable House Democrats who are beginning to hotfoot a bit around the oven surface.

Here’s one:

“Give Trump the money,” Rep. Collin Peterson (D-Minn.), whose district Trump won by 30 points in 2016, said in an interview with Fargo, N.D.-based radio station KFGO. “I’d give him the whole thing . . . and put strings on it so you make sure he puts the wall where it needs to be. Why are we fighting over this? We’re going to build that wall anyway, at some time.”

On the other hand, Rep. Peterson votes with the Republicans more than any other Democrat in Congress. He’s more like the first bubble in a heated pot than a real indication that the Democrats are approaching a breaking point.

To the contrary, the clear downward movement in Trump’s polls has to be highly encouraging to the Democrats because nothing prior to this has broken through the president’s seeming impregnable floor of support. Their strategy for the shutdown is working better than anything they’ve done before, at least as a strictly political matter. That weighs heavily when they consider how much more constituent pain they can endure.

Speaker Pelosi is holding firm that there will be no negotiations until the government is reopened, and she reiterated today that the president is not permitted to give his State of the Union in the Capitol if the people in charge of security aren’t getting paid because of lack of funding. She’s clearly in the driver’s seat right now.